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-rw-r--r--Documentation/gpio/consumer.txt26
-rw-r--r--drivers/gpio/devres.c40
-rw-r--r--drivers/gpio/gpiolib.c67
-rw-r--r--include/linux/gpio/consumer.h81
4 files changed, 155 insertions, 59 deletions
diff --git a/Documentation/gpio/consumer.txt b/Documentation/gpio/consumer.txt
index d8abfc31abbe..76546324e968 100644
--- a/Documentation/gpio/consumer.txt
+++ b/Documentation/gpio/consumer.txt
@@ -29,13 +29,24 @@ gpiod_get() functions. Like many other kernel subsystems, gpiod_get() takes the
device that will use the GPIO and the function the requested GPIO is supposed to
fulfill:
- struct gpio_desc *gpiod_get(struct device *dev, const char *con_id)
+ struct gpio_desc *gpiod_get(struct device *dev, const char *con_id,
+ enum gpiod_flags flags)
If a function is implemented by using several GPIOs together (e.g. a simple LED
device that displays digits), an additional index argument can be specified:
struct gpio_desc *gpiod_get_index(struct device *dev,
- const char *con_id, unsigned int idx)
+ const char *con_id, unsigned int idx,
+ enum gpiod_flags flags)
+
+The flags parameter is used to optionally specify a direction and initial value
+for the GPIO. Values can be:
+
+* GPIOD_ASIS or 0 to not initialize the GPIO at all. The direction must be set
+ later with one of the dedicated functions.
+* GPIOD_IN to initialize the GPIO as input.
+* GPIOD_OUT_LOW to initialize the GPIO as output with a value of 0.
+* GPIOD_OUT_HIGH to initialize the GPIO as output with a value of 1.
Both functions return either a valid GPIO descriptor, or an error code checkable
with IS_ERR() (they will never return a NULL pointer). -ENOENT will be returned
@@ -46,11 +57,13 @@ errors and an absence of GPIO for optional GPIO parameters.
Device-managed variants of these functions are also defined:
- struct gpio_desc *devm_gpiod_get(struct device *dev, const char *con_id)
+ struct gpio_desc *devm_gpiod_get(struct device *dev, const char *con_id,
+ enum gpiod_flags flags)
struct gpio_desc *devm_gpiod_get_index(struct device *dev,
const char *con_id,
- unsigned int idx)
+ unsigned int idx,
+ enum gpiod_flags flags)
A GPIO descriptor can be disposed of using the gpiod_put() function:
@@ -67,8 +80,9 @@ Using GPIOs
Setting Direction
-----------------
-The first thing a driver must do with a GPIO is setting its direction. This is
-done by invoking one of the gpiod_direction_*() functions:
+The first thing a driver must do with a GPIO is setting its direction. If no
+direction-setting flags have been given to gpiod_get*(), this is done by
+invoking one of the gpiod_direction_*() functions:
int gpiod_direction_input(struct gpio_desc *desc)
int gpiod_direction_output(struct gpio_desc *desc, int value)
diff --git a/drivers/gpio/devres.c b/drivers/gpio/devres.c
index 65978cf85f79..41b2f40578d5 100644
--- a/drivers/gpio/devres.c
+++ b/drivers/gpio/devres.c
@@ -39,47 +39,53 @@ static int devm_gpiod_match(struct device *dev, void *res, void *data)
* devm_gpiod_get - Resource-managed gpiod_get()
* @dev: GPIO consumer
* @con_id: function within the GPIO consumer
+ * @flags: optional GPIO initialization flags
*
* Managed gpiod_get(). GPIO descriptors returned from this function are
* automatically disposed on driver detach. See gpiod_get() for detailed
* information about behavior and return values.
*/
-struct gpio_desc *__must_check devm_gpiod_get(struct device *dev,
- const char *con_id)
+struct gpio_desc *__must_check __devm_gpiod_get(struct device *dev,
+ const char *con_id,
+ enum gpiod_flags flags)
{
- return devm_gpiod_get_index(dev, con_id, 0);
+ return devm_gpiod_get_index(dev, con_id, 0, flags);
}
-EXPORT_SYMBOL(devm_gpiod_get);
+EXPORT_SYMBOL(__devm_gpiod_get);
/**
* devm_gpiod_get_optional - Resource-managed gpiod_get_optional()
* @dev: GPIO consumer
* @con_id: function within the GPIO consumer
+ * @flags: optional GPIO initialization flags
*
* Managed gpiod_get_optional(). GPIO descriptors returned from this function
* are automatically disposed on driver detach. See gpiod_get_optional() for
* detailed information about behavior and return values.
*/
-struct gpio_desc *__must_check devm_gpiod_get_optional(struct device *dev,
- const char *con_id)
+struct gpio_desc *__must_check __devm_gpiod_get_optional(struct device *dev,
+ const char *con_id,
+ enum gpiod_flags flags)
{
- return devm_gpiod_get_index_optional(dev, con_id, 0);
+ return devm_gpiod_get_index_optional(dev, con_id, 0, flags);
}
-EXPORT_SYMBOL(devm_gpiod_get_optional);
+EXPORT_SYMBOL(__devm_gpiod_get_optional);
/**
* devm_gpiod_get_index - Resource-managed gpiod_get_index()
* @dev: GPIO consumer
* @con_id: function within the GPIO consumer
* @idx: index of the GPIO to obtain in the consumer
+ * @flags: optional GPIO initialization flags
*
* Managed gpiod_get_index(). GPIO descriptors returned from this function are
* automatically disposed on driver detach. See gpiod_get_index() for detailed
* information about behavior and return values.
*/
-struct gpio_desc *__must_check devm_gpiod_get_index(struct device *dev,
+struct gpio_desc *__must_check __devm_gpiod_get_index(struct device *dev,
const char *con_id,
- unsigned int idx)
+ unsigned int idx,
+ enum gpiod_flags flags)
{
struct gpio_desc **dr;
struct gpio_desc *desc;
@@ -89,7 +95,7 @@ struct gpio_desc *__must_check devm_gpiod_get_index(struct device *dev,
if (!dr)
return ERR_PTR(-ENOMEM);
- desc = gpiod_get_index(dev, con_id, idx);
+ desc = gpiod_get_index(dev, con_id, idx, flags);
if (IS_ERR(desc)) {
devres_free(dr);
return desc;
@@ -100,26 +106,28 @@ struct gpio_desc *__must_check devm_gpiod_get_index(struct device *dev,
return desc;
}
-EXPORT_SYMBOL(devm_gpiod_get_index);
+EXPORT_SYMBOL(__devm_gpiod_get_index);
/**
* devm_gpiod_get_index_optional - Resource-managed gpiod_get_index_optional()
* @dev: GPIO consumer
* @con_id: function within the GPIO consumer
* @index: index of the GPIO to obtain in the consumer
+ * @flags: optional GPIO initialization flags
*
* Managed gpiod_get_index_optional(). GPIO descriptors returned from this
* function are automatically disposed on driver detach. See
* gpiod_get_index_optional() for detailed information about behavior and
* return values.
*/
-struct gpio_desc *__must_check devm_gpiod_get_index_optional(struct device *dev,
+struct gpio_desc *__must_check __devm_gpiod_get_index_optional(struct device *dev,
const char *con_id,
- unsigned int index)
+ unsigned int index,
+ enum gpiod_flags flags)
{
struct gpio_desc *desc;
- desc = devm_gpiod_get_index(dev, con_id, index);
+ desc = devm_gpiod_get_index(dev, con_id, index, flags);
if (IS_ERR(desc)) {
if (PTR_ERR(desc) == -ENOENT)
return NULL;
@@ -127,7 +135,7 @@ struct gpio_desc *__must_check devm_gpiod_get_index_optional(struct device *dev,
return desc;
}
-EXPORT_SYMBOL(devm_gpiod_get_index_optional);
+EXPORT_SYMBOL(__devm_gpiod_get_index_optional);
/**
* devm_gpiod_put - Resource-managed gpiod_put()
diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index 330227581a25..15cc0bb65dda 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -1582,38 +1582,43 @@ static struct gpio_desc *gpiod_find(struct device *dev, const char *con_id,
* gpiod_get - obtain a GPIO for a given GPIO function
* @dev: GPIO consumer, can be NULL for system-global GPIOs
* @con_id: function within the GPIO consumer
+ * @flags: optional GPIO initialization flags
*
* Return the GPIO descriptor corresponding to the function con_id of device
* dev, -ENOENT if no GPIO has been assigned to the requested function, or
* another IS_ERR() code if an error occured while trying to acquire the GPIO.
*/
-struct gpio_desc *__must_check gpiod_get(struct device *dev, const char *con_id)
+struct gpio_desc *__must_check __gpiod_get(struct device *dev, const char *con_id,
+ enum gpiod_flags flags)
{
- return gpiod_get_index(dev, con_id, 0);
+ return gpiod_get_index(dev, con_id, 0, flags);
}
-EXPORT_SYMBOL_GPL(gpiod_get);
+EXPORT_SYMBOL_GPL(__gpiod_get);
/**
* gpiod_get_optional - obtain an optional GPIO for a given GPIO function
* @dev: GPIO consumer, can be NULL for system-global GPIOs
* @con_id: function within the GPIO consumer
+ * @flags: optional GPIO initialization flags
*
* This is equivalent to gpiod_get(), except that when no GPIO was assigned to
* the requested function it will return NULL. This is convenient for drivers
* that need to handle optional GPIOs.
*/
-struct gpio_desc *__must_check gpiod_get_optional(struct device *dev,
- const char *con_id)
+struct gpio_desc *__must_check __gpiod_get_optional(struct device *dev,
+ const char *con_id,
+ enum gpiod_flags flags)
{
- return gpiod_get_index_optional(dev, con_id, 0);
+ return gpiod_get_index_optional(dev, con_id, 0, flags);
}
-EXPORT_SYMBOL_GPL(gpiod_get_optional);
+EXPORT_SYMBOL_GPL(__gpiod_get_optional);
/**
* gpiod_get_index - obtain a GPIO from a multi-index GPIO function
* @dev: GPIO consumer, can be NULL for system-global GPIOs
* @con_id: function within the GPIO consumer
* @idx: index of the GPIO to obtain in the consumer
+ * @flags: optional GPIO initialization flags
*
* This variant of gpiod_get() allows to access GPIOs other than the first
* defined one for functions that define several GPIOs.
@@ -1622,23 +1627,24 @@ EXPORT_SYMBOL_GPL(gpiod_get_optional);
* requested function and/or index, or another IS_ERR() code if an error
* occured while trying to acquire the GPIO.
*/
-struct gpio_desc *__must_check gpiod_get_index(struct device *dev,
+struct gpio_desc *__must_check __gpiod_get_index(struct device *dev,
const char *con_id,
- unsigned int idx)
+ unsigned int idx,
+ enum gpiod_flags flags)
{
struct gpio_desc *desc = NULL;
int status;
- enum gpio_lookup_flags flags = 0;
+ enum gpio_lookup_flags lookupflags = 0;
dev_dbg(dev, "GPIO lookup for consumer %s\n", con_id);
/* Using device tree? */
if (IS_ENABLED(CONFIG_OF) && dev && dev->of_node) {
dev_dbg(dev, "using device tree for GPIO lookup\n");
- desc = of_find_gpio(dev, con_id, idx, &flags);
+ desc = of_find_gpio(dev, con_id, idx, &lookupflags);
} else if (IS_ENABLED(CONFIG_ACPI) && dev && ACPI_HANDLE(dev)) {
dev_dbg(dev, "using ACPI for GPIO lookup\n");
- desc = acpi_find_gpio(dev, con_id, idx, &flags);
+ desc = acpi_find_gpio(dev, con_id, idx, &lookupflags);
}
/*
@@ -1647,7 +1653,7 @@ struct gpio_desc *__must_check gpiod_get_index(struct device *dev,
*/
if (!desc || desc == ERR_PTR(-ENOENT)) {
dev_dbg(dev, "using lookup tables for GPIO lookup");
- desc = gpiod_find(dev, con_id, idx, &flags);
+ desc = gpiod_find(dev, con_id, idx, &lookupflags);
}
if (IS_ERR(desc)) {
@@ -1660,16 +1666,33 @@ struct gpio_desc *__must_check gpiod_get_index(struct device *dev,
if (status < 0)
return ERR_PTR(status);
- if (flags & GPIO_ACTIVE_LOW)
+ if (lookupflags & GPIO_ACTIVE_LOW)
set_bit(FLAG_ACTIVE_LOW, &desc->flags);
- if (flags & GPIO_OPEN_DRAIN)
+ if (lookupflags & GPIO_OPEN_DRAIN)
set_bit(FLAG_OPEN_DRAIN, &desc->flags);
- if (flags & GPIO_OPEN_SOURCE)
+ if (lookupflags & GPIO_OPEN_SOURCE)
set_bit(FLAG_OPEN_SOURCE, &desc->flags);
+ /* No particular flag request, return here... */
+ if (flags & GPIOD_FLAGS_BIT_DIR_SET)
+ return desc;
+
+ /* Process flags */
+ if (flags & GPIOD_FLAGS_BIT_DIR_OUT)
+ status = gpiod_direction_output(desc,
+ flags & GPIOD_FLAGS_BIT_DIR_VAL);
+ else
+ status = gpiod_direction_input(desc);
+
+ if (status < 0) {
+ dev_dbg(dev, "setup of GPIO %s failed\n", con_id);
+ gpiod_put(desc);
+ return ERR_PTR(status);
+ }
+
return desc;
}
-EXPORT_SYMBOL_GPL(gpiod_get_index);
+EXPORT_SYMBOL_GPL(__gpiod_get_index);
/**
* gpiod_get_index_optional - obtain an optional GPIO from a multi-index GPIO
@@ -1677,18 +1700,20 @@ EXPORT_SYMBOL_GPL(gpiod_get_index);
* @dev: GPIO consumer, can be NULL for system-global GPIOs
* @con_id: function within the GPIO consumer
* @index: index of the GPIO to obtain in the consumer
+ * @flags: optional GPIO initialization flags
*
* This is equivalent to gpiod_get_index(), except that when no GPIO with the
* specified index was assigned to the requested function it will return NULL.
* This is convenient for drivers that need to handle optional GPIOs.
*/
-struct gpio_desc *__must_check gpiod_get_index_optional(struct device *dev,
+struct gpio_desc *__must_check __gpiod_get_index_optional(struct device *dev,
const char *con_id,
- unsigned int index)
+ unsigned int index,
+ enum gpiod_flags flags)
{
struct gpio_desc *desc;
- desc = gpiod_get_index(dev, con_id, index);
+ desc = gpiod_get_index(dev, con_id, index, flags);
if (IS_ERR(desc)) {
if (PTR_ERR(desc) == -ENOENT)
return NULL;
@@ -1696,7 +1721,7 @@ struct gpio_desc *__must_check gpiod_get_index_optional(struct device *dev,
return desc;
}
-EXPORT_SYMBOL_GPL(gpiod_get_index_optional);
+EXPORT_SYMBOL_GPL(__gpiod_get_index_optional);
/**
* gpiod_put - dispose of a GPIO descriptor
diff --git a/include/linux/gpio/consumer.h b/include/linux/gpio/consumer.h
index 05e53ccb708b..b7ce0c64c6f3 100644
--- a/include/linux/gpio/consumer.h
+++ b/include/linux/gpio/consumer.h
@@ -18,30 +18,79 @@ struct gpio_desc;
#ifdef CONFIG_GPIOLIB
+#define GPIOD_FLAGS_BIT_DIR_SET BIT(0)
+#define GPIOD_FLAGS_BIT_DIR_OUT BIT(1)
+#define GPIOD_FLAGS_BIT_DIR_VAL BIT(2)
+
+/**
+ * Optional flags that can be passed to one of gpiod_* to configure direction
+ * and output value. These values cannot be OR'd.
+ */
+enum gpiod_flags {
+ GPIOD_ASIS = 0,
+ GPIOD_IN = GPIOD_FLAGS_BIT_DIR_SET,
+ GPIOD_OUT_LOW = GPIOD_FLAGS_BIT_DIR_SET | GPIOD_FLAGS_BIT_DIR_OUT,
+ GPIOD_OUT_HIGH = GPIOD_FLAGS_BIT_DIR_SET | GPIOD_FLAGS_BIT_DIR_OUT |
+ GPIOD_FLAGS_BIT_DIR_VAL,
+};
+
/* Acquire and dispose GPIOs */
-struct gpio_desc *__must_check gpiod_get(struct device *dev,
- const char *con_id);
-struct gpio_desc *__must_check gpiod_get_index(struct device *dev,
+struct gpio_desc *__must_check __gpiod_get(struct device *dev,
+ const char *con_id,
+ enum gpiod_flags flags);
+#define __gpiod_get(dev, con_id, flags, ...) __gpiod_get(dev, con_id, flags)
+#define gpiod_get(varargs...) __gpiod_get(varargs, 0)
+struct gpio_desc *__must_check __gpiod_get_index(struct device *dev,
const char *con_id,
- unsigned int idx);
-struct gpio_desc *__must_check gpiod_get_optional(struct device *dev,
- const char *con_id);
-struct gpio_desc *__must_check gpiod_get_index_optional(struct device *dev,
+ unsigned int idx,
+ enum gpiod_flags flags);
+#define __gpiod_get_index(dev, con_id, index, flags, ...) \
+ __gpiod_get_index(dev, con_id, index, flags)
+#define gpiod_get_index(varargs...) __gpiod_get_index(varargs, 0)
+struct gpio_desc *__must_check __gpiod_get_optional(struct device *dev,
+ const char *con_id,
+ enum gpiod_flags flags);
+#define __gpiod_get_optional(dev, con_id, flags, ...) \
+ __gpiod_get_optional(dev, con_id, flags)
+#define gpiod_get_optional(varargs...) __gpiod_get_optional(varargs, 0)
+struct gpio_desc *__must_check __gpiod_get_index_optional(struct device *dev,
const char *con_id,
- unsigned int index);
+ unsigned int index,
+ enum gpiod_flags flags);
+#define __gpiod_get_index_optional(dev, con_id, index, flags, ...) \
+ __gpiod_get_index_optional(dev, con_id, index, flags)
+#define gpiod_get_index_optional(varargs...) \
+ __gpiod_get_index_optional(varargs, 0)
void gpiod_put(struct gpio_desc *desc);
-struct gpio_desc *__must_check devm_gpiod_get(struct device *dev,
- const char *con_id);
-struct gpio_desc *__must_check devm_gpiod_get_index(struct device *dev,
+struct gpio_desc *__must_check __devm_gpiod_get(struct device *dev,
+ const char *con_id,
+ enum gpiod_flags flags);
+#define __devm_gpiod_get(dev, con_id, flags, ...) \
+ __devm_gpiod_get(dev, con_id, flags)
+#define devm_gpiod_get(varargs...) __devm_gpiod_get(varargs, 0)
+struct gpio_desc *__must_check __devm_gpiod_get_index(struct device *dev,
const char *con_id,
- unsigned int idx);
-struct gpio_desc *__must_check devm_gpiod_get_optional(struct device *dev,
- const char *con_id);
+ unsigned int idx,
+ enum gpiod_flags flags);
+#define __devm_gpiod_get_index(dev, con_id, index, flags, ...) \
+ __devm_gpiod_get_index(dev, con_id, index, flags)
+#define devm_gpiod_get_index(varargs...) __devm_gpiod_get_index(varargs, 0)
+struct gpio_desc *__must_check __devm_gpiod_get_optional(struct device *dev,
+ const char *con_id,
+ enum gpiod_flags flags);
+#define __devm_gpiod_get_optional(dev, con_id, flags, ...) \
+ __devm_gpiod_get_optional(dev, con_id, flags)
+#define devm_gpiod_get_optional(varargs...) \
+ __devm_gpiod_get_optional(varargs, 0)
struct gpio_desc *__must_check
-devm_gpiod_get_index_optional(struct device *dev, const char *con_id,
- unsigned int index);
+__devm_gpiod_get_index_optional(struct device *dev, const char *con_id,
+ unsigned int index, enum gpiod_flags flags);
+#define __devm_gpiod_get_index_optional(dev, con_id, index, flags, ...) \
+ __devm_gpiod_get_index_optional(dev, con_id, index, flags)
+#define devm_gpiod_get_index_optional(varargs...) \
+ __devm_gpiod_get_index_optional(varargs, 0)
void devm_gpiod_put(struct device *dev, struct gpio_desc *desc);

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